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| author | Thierry Reding <treding@nvidia.com> | 2019-02-01 14:28:29 +0100 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2019-02-07 18:28:58 +0100 |
| commit | 0e43b8da154a95f4369da4068a43ad9d700f4cea (patch) | |
| tree | 25b86a7d2e0c567f2e4d77360fce720cc99519f9 /drivers/gpu/host1x | |
| parent | 8de896eb206fea3caa26b5fc8e637934d8486f0f (diff) | |
| download | lwn-0e43b8da154a95f4369da4068a43ad9d700f4cea.tar.gz lwn-0e43b8da154a95f4369da4068a43ad9d700f4cea.zip | |
gpu: host1x: Use correct semantics for HOST1X_CHANNEL_DMAEND
The HOST1X_CHANNEL_DMAEND is an offset relative to the value written to
the HOST1X_CHANNEL_DMASTART register, but it is currently treated as an
absolute address. This can cause SMMU faults if the CDMA fetches past a
pushbuffer's IOMMU mapping.
Properly setting the DMAEND prevents the CDMA from fetching beyond that
address and avoid such issues. This is currently not observed because a
whole (almost) page of essentially scratch space absorbs any excessive
prefetching by CDMA. However, changing the number of slots in the push
buffer can trigger these SMMU faults.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/host1x')
| -rw-r--r-- | drivers/gpu/host1x/hw/cdma_hw.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/host1x/hw/cdma_hw.c b/drivers/gpu/host1x/hw/cdma_hw.c index 485aef5761af..a24c090ac96f 100644 --- a/drivers/gpu/host1x/hw/cdma_hw.c +++ b/drivers/gpu/host1x/hw/cdma_hw.c @@ -75,7 +75,7 @@ static void cdma_start(struct host1x_cdma *cdma) cdma->last_pos = cdma->push_buffer.pos; start = cdma->push_buffer.dma; - end = start + cdma->push_buffer.size + 4; + end = cdma->push_buffer.size + 4; host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP, HOST1X_CHANNEL_DMACTRL); @@ -126,7 +126,7 @@ static void cdma_timeout_restart(struct host1x_cdma *cdma, u32 getptr) HOST1X_CHANNEL_DMACTRL); start = cdma->push_buffer.dma; - end = start + cdma->push_buffer.size + 4; + end = cdma->push_buffer.size + 4; /* set base, end pointer (all of memory) */ host1x_ch_writel(ch, lower_32_bits(start), HOST1X_CHANNEL_DMASTART); |